SQLite

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.544 2009/01/09 17:11:05 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"

/*
** Macros for troubleshooting.  Normally turned off
*/

    assert( sqlite3PcacheRefCount(pPager->pPCache)==0 );
    if( !pPager->noReadlock ){
      rc = pager_wait_on_lock(pPager, SHARED_LOCK);
      if( rc!=SQLITE_OK ){
        assert( pPager->state==PAGER_UNLOCK );
        return pager_error(pPager, rc);
      }
    }else if( pPager->state==PAGER_UNLOCK ){
      pPager->state = PAGER_SHARED;
    }
    assert( pPager->state>=SHARED_LOCK );

    /* If a journal file exists, and there is no RESERVED lock on the
    ** database file, then it either needs to be played back or deleted.
    */
    if( !isErrorReset ){
      rc = hasHotJournal(pPager, &isHotJournal);
      if( rc!=SQLITE_OK ){

        memset(dbFileVers, 0, sizeof(dbFileVers));
      }

      if( memcmp(pPager->dbFileVers, dbFileVers, sizeof(dbFileVers))!=0 ){
        pager_reset(pPager);
      }
    }
    assert( pPager->exclusiveMode || pPager->state==PAGER_SHARED );



  }

 failed:
  if( rc!=SQLITE_OK ){
    /* pager_unlock() is a no-op for exclusive mode and in-memory databases. */
    pager_unlock(pPager);
  }

# 2006 September 4
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# $Id: misc7.test,v 1.26 2009/01/09 17:11:05 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test misc7-1-misuse {
  c_misuse_test
} {}

    SELECT name FROM aux.sqlite_master;
  }
} {hello}
do_test misc7-7.2 {
  execsql {
    DETACH aux;
  }
} {}
do_test misc7-7.3 {
  db close
  sqlite3 db test.db -readonly 1
  execsql {
    PRAGMA omit_readlock = 1;
    ATTACH 'test2.db' AS aux;
    SELECT name FROM aux.sqlite_master;
    SELECT name FROM aux.sqlite_master;
  }
} {hello hello}
do_test misc7-7.3 {
  db close
  sqlite3 db test.db
  set ::DB [sqlite3_connection_pointer db]
  list
} {}

# Test the UTF-16 version of the "out of memory" message (used when
# malloc fails during sqlite3_open() ).
#
ifcapable utf16 {
  do_test misc7-8 {

# sqlite3_global_recover() is a no-op.  But we might as well test it
# if only to get the test coverage.
#
do_test misc7-20.1 {
  sqlite3_global_recover
} {SQLITE_OK}

# Try to open a really long file name.
#
do_test misc7-21.1 {
  set zFile [file join [pwd] "[string repeat abcde 104].db"]
  set rc [catch {sqlite3 db2 $zFile} msg]
  list $rc $msg
} {1 {unable to open database file}}


db close
file delete -force test.db

finish_test

# 2008 December 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# $Id: savepoint3.test,v 1.4 2009/01/09 17:11:05 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

source $testdir/malloc_common.tcl

do_malloc_test savepoint3-1 -sqlprep {

  COMMIT;
} -cleanup {
  db eval {
    SAVEPOINT one;
    RELEASE one;
  }
}

# The following test does a really big savepoint rollback. One involving
# more than 4000 pages. The idea is to get a specific sqlite3BitvecSet()
# operation in pagerPlaybackSavepoint() to fail.
#do_malloc_test savepoint3-4 -sqlprep {
#  BEGIN;
#    CREATE TABLE t1(a, b);
#    CREATE INDEX i1 ON t1(a);
#    CREATE INDEX i2 ON t1(b);
#    INSERT INTO t1 VALUES(randstr(500,500), randstr(500,500));        --     1
#    INSERT INTO t1 VALUES(randstr(500,500), randstr(500,500));        --     2
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --     4
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --     8
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --    16
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --    32
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --    64
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --   128
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --   256
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --   512
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --  1024
#    INSERT INTO t1 SELECT randstr(500,500), randstr(500,500) FROM t1; --  2048
#  COMMIT;
#  BEGIN;
#    SAVEPOINT abc;
#      UPDATE t1 SET a = randstr(500,500);
#} -sqlbody {
#    ROLLBACK TO abc;
#}


# Cause a specific malloc in savepoint rollback code to fail.
#
do_malloc_test savepoint3-4 -start 7 -sqlprep {
  PRAGMA auto_vacuum = incremental;
  PRAGMA cache_size = 1000;

  CREATE TABLE t1(a, b);
  CREATE TABLE t2(a, b);
  CREATE TABLE t3(a, b);
  INSERT INTO t1 VALUES(1, randstr(500,500));
  INSERT INTO t1 VALUES(2, randstr(500,500));
  INSERT INTO t1 VALUES(3, randstr(500,500));
  DELETE FROM t1;

  BEGIN;
    INSERT INTO t1 VALUES(1, randstr(500,500));
    INSERT INTO t1 VALUES(2, randstr(500,500));
    INSERT INTO t1 VALUES(3, randstr(500,500));
    DROP TABLE t3;                  -- Page 5 of the database file is now free.
    DROP TABLE t2;                  -- Page 4 of the database file is now free.

    SAVEPOINT abc;
      PRAGMA incremental_vacuum;
} -sqlbody {
  ROLLBACK TO abc;
}


finish_test